bombs or grenades of shooter action games, these spells allow Ryu to inflict heavy damage on enemies while potentially avoiding damage himself. But, dissatisfied with their programmed visual effects, the game's director Tomonobu Itagaki wanted to deter players from using ninpo. He therefore tweaked the game to award bonus points when players cleared stages without employing magic. For Ryu's defense, the player has two options. First, Ryu can stand still and attempt to block attacks. However, certain enemies can break his guard—either through particularly strong attacks or by grappling him. The second option is to make Ryu dodge, by rolling away from the attack in a maneuver called "reverse wind". Plot Inspired by the 1980s Ninja Gaiden series for the Nintendo Entertainment System (NES), the 2004 version was originally set in a re-imagined game world based on another Team Ninja creation, the Dead or Alive (DOA) series of fighting games. However, interviews with Tomonobu Itagaki indicate that the Xbox games are prequels to the NES series and that both possibly share a single continuity. Ninja Gaiden is set in the game world of the Dead or Alive series. Located mainly in Japan and the fictional Western Asian nation of the Vigoor Empire, the game draws on Heian period structures for its Japanese locales—a ninja fortress and village set in the mountains. In contrast the Vigoor Empire, with its capital city of Tairon, is a blend of architectural types from around the world. European-style buildings display Arabic lettering, and the monastery in Tairon exhibits Gothic influences with a vaulted hall, pointed arches, and large stained glass windows. A hidden underground level features statues with the heads of cats, walls covered with carvings, hieroglyphics, Aztec pyramid and a labyrinth. This mix of styles was the result of Itagaki's refusal to constrain the game's creative process. Characters Ryu Hayabusa, the "super ninja", is the protagonist of Ninja Gaiden, and the primary player-controllable character in the game. Itagaki believed that creating extra player characters might distract his team from focusing on Ryu's development, despite this, Rachel is a playable character in the Sigma version of the game. Ryu has a long history with Tecmo; he was the star of the 1990s Ninja Gaiden series, and has been part of the DOA roster since 1996. His roles in these games played a part in his popularity among fans and the video game industry. Ninja Gaiden